Preparation of carboxylic acid amides

ABSTRACT

A METHOD FOR THE PRODUCTION OF N-SUBSTITUTED AMIDES OF FATTY ACIDS OF 8 TO 24 CARBON ATOMS BY REACTING THE FREE CARBOXYLIC ACIDS OR THEIR ESTERS WITH AMINED IN THE PREXENCE OF CATALYSTS CONSISTING OF COMPOUNDS OF METALS OF THE GROUP IVB AND VB OF THE PERIODIC TABLE WHICH ARE SOLUBLE IN THE REACTION MIXTURE.

United States Patent M 3,801,610 PREPARATION OF CARBOXYLIC ACID AMIDES Achim Werdehausen, Monheim, and Herbert Weiss, Cologne-Deutz, Germany, assignors to Henkel & Cie., G.m.b.H., Dusseldorf, Germany N0 Drawing. Filed May 24, 1971, Ser. No. 146,564 Claims priority, application Germany, Mar. 3, 1971, P 21 060.7 Int. Cl. C07c 103/30 US. Cl. 260-404 8 Claims ABSTRACT OF THE DISCLOSURE A method for the production of N-substituted amides of fatty acids of 8 to 24 carbon atoms by reacting the free carboxylic acids or their esters with amines in the presence of catalysts consisting of compounds of metals of the Group IVb and Vb of the Periodic Table which are soluble in the reaction mixture.

OBI ECT S OF THE INVENTION It is an object of the invention to provide a novel process for the production of N-substituted amides of higher fatty acids in good yields and in reduced reaction time.

It is a further object of the invention to provide an improved process for the reaction of amines and higher fatty acids in the presence of catalysts of metals of Groups IVb and Vb of the Periodic Table.

These and other objects and advantages of the invention will become obvious from the following detailed description.

THE INVENTION The novel process of the invention for the preparation of N-substituted amides of fatty acids comprises reacting a primary or secondary amine with a member of the group consisting of aliphatic carboxylic acids of 8 to 24 carbon atoms and esters thereof with aliphatic alcohols in the presence of a reaction-soluble, catalyst compound of a metal of Groups IVb and Vb of the Periodic Table. The process of the invention has the advantage of reduced reaction time as compared to known processes, and a high quality product practically free of by-products or unreacted starting material, and having excellent color quality.

Among the compounds ofthe metals that are suitable as catalysts are soluble metal compounds formed in the reaction mixture from finely dispersed metal, for example, ground tin; (a) the esters of the corresponding orthoacids particularly with primary and secondary aliphatic alcohols which contain preferably 1-18 carbon atoms, e.g. methanol, ethanol, nand iso-propanol, nand isobutanol, Z-ethyl-hexanol-l, lauryl alcohol, stearyl alcohol, synthetic alcohol mixtures from 0x0 and Ziegler processes and ether and polyether alcohols, as they can be produced by alkoxylation reactions of substances With active H- atoms; (in) complex compounds with 1,3-diketones, such as 3 methylpentanedione (2,4),3-ethylpentanedione- (2,4), heptanedion-(2,4), decanedion-(2,4) and particularly pentanedione-(2,4) (acetyl acetone); (c) halogen compounds of the metals in their highest valence stage, particularly chlorine compounds; and (d) acyl compounds as they can be produced by reacting the halides with metal salts of carboxylic acids in known manner, for example, by the method of US. Pats. 2,132,999, 2,489,651 and 2,621,195, and which are partly present in polymeric form containing groups similar to the gels formed by intermolecular dehydration from the orthometallic acids. Such compounds are generally called metal-polyhydroxy acylates.

3,801,610 Patented Apr. 2 1974 LticlLH .L Lani.

wherein R is hydrogen or acyl of an organic carboxylic acid and at least one of m, n and o is an integral number, and the others may be zero or an integral number, and Ac is acyl of an organic carboxylic acid, preferably stearoyl, tetra-n-propyl zirconate, tetra-isobutyl zirconate, tetra-n-butyl zirconate, titanium acetyl acetonate, zirconium acetyl acetonate, titanium tetrachloride, zirconium tetrachloride, tantalum pentachloride. Of the above described catalysts, the complex compounds of the 1,3- diketones, primarily of acetyl acetone, are particularly advantageous because of their resistance to hydrolysis.

The catalysts are added to the reaction mixture in quantities of 0.1 to 10, preferably 0.5 to 5% by weight, related to the carboxylic acid or carboxylic ester to be reacted.

The reaction can be carried out with primary and secondary aliphatic cycloaliphatic or mixed aliphatic/cycloaliphatic amines such as: (a) primary and secondary aliphatic amines with 1 to 24 C-atoms in the alkyl radicals, like methylamine, dimethylamine, monoand diethylamine, monoand diethanolamine, methyl-dodecyl amine, didodecyl amine, octadecyl amine, methyl octadecyl amine, erucyl amine, behenyl amine, as well as fatty amine mixtures, as can be obtained in known manner, for example, from natural fatty acid mixtures; (b) cycle-- aliphatic and mixed aliphatic/cycloaliphatic amines, like cyclohexyl amine, methyl cyclohexyl amine; (c) aliphatic and/ or cycloaliphatic diand polyamines or polyalkylene polyamines, like ethylene diamine, hexamethylene diamine, heptamethylene diamine, octamethylene diamine, propylene diamine, diethylene triamine, triethylene tetramine, tetraethylene-pentamine, diand tri-amino-cyclohexanes.

In the method according to the invention, the aliphatic carboxylic acids to be reacted may be straight-chained and branched saturated and unsaturated aliphatic carboxylic acids with 8 to 22 carbon atoms as well as corresponding hydroxy-carboxylic acids, for example, lauric acid, myritic acid, palmitic acid, stearic acid, arachic acid, ricinoleic acid, hydroxystearic acids from the hydroxylation of oleic acid, behenic acid, lignoceric acid, oleic acid, erucic acid, linoleic acid, linolenic acid, arachidonic acid, ricinoleic acid, ricinenic acid, capric acid, caprylic acid, straight-chained and branched chain carboxylic acid of synthetic origin, for example, the carboxylic acids obtained by oxidation or paratfins in the presence of boric acid or by oxo-reduction, cyclic carboxylic acids like naphthenic acid, resinic acids or polymeric carboxylic acids obtained by polymerization of unsaturated carboxylic acids. These carboxylic acids can be used individually or in mixture with each other as starting materials. Carboxylic acids which are suitable as starting materials can be produced in known manner by saponification of natural triglyceride mixtures, for example, coconut oil, cottonseed oil, linseed oil, olive oil, palm oil, palm kernel oil, soy bean oil, tall oil, lard, beef tallow, fish oil and castor oil.

As starting materials which can also be reacted in the method are the esters of the above-mentioned carboxylic acids with monovalent aliphatic alcohols. Preferred are the esters of alcohols with l to 4 carbon atoms, since these esters, particularly the methyl esters, are commercially available as re-esterification mixtures of natural triglyceride mixtures. If such esters or their homolog mixtures tion. This is of particular importance in the reaction of high-boiling amines in the liquid phase where such a measure would mean an additional expenditure. Both with the use of highly volatile and of high-boiling amines, the reaction can be carried out under normal pressure.

are used, there can be an additional N-alkylation by 5 The end products can be used in many ways, for exfurther reaction of the first .formed carboxylic amides ample, as detergent ingredients, crystallization aids or as with the alcohol released during the reaction. solvents for inorganic and organic substances, such as The reaction between amines and aliphatic carboxylic polymers. They represent furthermore valuable interacids or their esters is carried out preferably in a tempermediate products, for example, for the production of ature range of 100 to 300 C. A higher temperature than surface-active substances and textile aids. The products 300 C. enhances a faster reaction while a lower than the derived from diand polyamines or polyalkylene-polyindicated temperature still permits a reaction, but it reamines are suitable as washing and plastic aids, for exquires unjustifiably long reaction times. Of particular ample, as lubricants and anti-blocking agents. advantage is a temperature range of 120 to 200 C. In the following examples there are described several When amines are used which volatilize easily at the preferred embodiments to illustrate the invention. Howrespective reaction temperatures, they are advantageously ever, it should be understood that the invention is not recycled whereby they simultaneously serve as an ent ed to be limi ed to the Specific embodiments. trainer for the water formed during the reaction, and The percentages of free acid and free amines indicated they are liberated of the entrained Water by installing in the following 674311117165 Were determined by titration cooling traps in the gas cycle. The introduction of the With bases against Phenolphthalein titration with amines volatilizing easily at the respective reaction temacids against bromophenol blue- The Lovibond C0101 perature can be efiected best at the bottom of the reacvalues Were measured in solutions p y W g tion vessel, particularly it they are preheated, which is Carboxylic amide in 5 Parts y Weight chloroform) using advisable particularly for larger charges, so that a very a cuvette at the Gardner 1 al s in t long contact of the amine with the carboxylic acid or melt With a V d- 0Inparat0rcarboxylic acid esters to be reacted is ensured. Suitable EXAMPLE 1 reaction vessels are particularly vertical reaction towers or tubes whose dimensions must be adapted to the avail- 500 of a commerclal fatty acld fr-actlon conslstmg able equipment and to the size of the charges. As reaction substantlauy of 0161c acid 03%, vessels, reactors with other dimensions can also be used C44 C46 42%, C48 I 792%: provided a sufficiently fine dispersion of the supplied gas and T C 20 19%; supply in the reaction mixture is ensured by a corre acid number 196.3; saponlfication number 197.2, iodine spending constructional design of the amine gas supply, numb turbidlty charged into for example, an intensive stirrer in front of the feed pipe. a ,round bottom flask Pmvlded with a stirrer and mixed The gaseous amine is introduced into the reaction mixwlth 5 by weight) of tetrapropyl Zirconateture, preferably in an amount which should not be less AftFr heating the mixture to dimethylamine, than 20 liters/kg. of carboxylic acid or carboxylic acid wh1c1 1waS Preheate d to C, was introduced into the ester an h The optimum amount and velocity of flow reaction mlxture with intensive stirring at a rate of flow are determined to a great extent by the available equip of 95 l./h. After two hours, the rate of flow of dimethylment and can also adapted to the reaction course For amine was reduced to l./h. The product, after a total example, at the start of the reaction, relatively large reaction time of 5 hours, contained 98.5% of the diamounts and high velocities of flow were used and are methyl amide, 137% of free unreacted acid and 011% slowly reduced with decreasing amine consumption of the 45 of free amine. The Lovibond color values of the product reaction i were yellow 5.0 and red 0.8.

In the reaction of higher or high-boiling amines such as coconutor tallow amine, it is possible to work in EXAMPLES simple stirringwessels with the necessary auxiliary de- The carboxylic acid used in Example 1 was reacted with v1ces, like a nitrogen atmosphere, condenser and water dimethylamine under similar conditions by varying the separator. T1118 reaction in the liquid phase can be carried reaction temperature and the results are in Table I.

TABLE I Reaction Percent Lovibond color values Example Temper- Time Acid Free Free No. a'ture 0.) (hours) number acid amine Amide Yellow Red 2 12 4.3 2.11 0.18 97.7 7.1 1.2 a 105 7.5 2.83 1.39 0.10 98.5 4.9 1.0 L 180 e 2. 31 1.13 0.10 98.8 2.9 0.0

out principally in equivalent quantitative ratios. Because 60 EXAMPLES 5-7 of the water vapor volatility of the amines used, which can be discharged with the water formed during the re- The carboxylic acid used in Example 1 was reacted action, the amines must be used in a molar excess of 5 to in the presence of 1% by weight of the catalysts men- 10% relative to the carboxylic acid or carboxylic acid tioned in the following table at C. with dimethylester used. The use of an entrainer for the water formed 65 amine in a procedure similar to that in Example 1. The in the reaction is not absolutely necessary in the invenresults are shown in Table II.

TABLE II Percent Lovibond Reaction color values Ex.- time Acid Free Free No. Catalyst (hours) number acid amine Amide Yellow Red 5 Titanium acetyl aeetonate 5 1.02 0.51 0.10 99.4 3.0 0.5 6 Titanium polyhydroxy stearate 6 1.20 0. 59 0.19 99.2 6.0 1.1 7 Tetraisopropyl titanate 5 0.91 0. 45 0.15 99.4 3.2 0.7

1103 1 compound with Ac= stearoyl.

5 EXAMPLES 8-12 The carboxylic acids in the following table were reacted in the presence of 1% by weight of tetrapropyl zirconate at 195 C. with dirnethylamine in a Procedure similar to Example 1. The results are in Table 1H.

TABLE III Percent Lovibond Reaction color Ex. time Acid Free Free No. Carboxylie acid (hours) number acid amine Amide Yellow Red 8 Laurie acid 6 1. 87 0. 64 0. 99. 4 1. 1 0. 1. 6 1. 46 .59 0. 0 99. 4 2. 0 0. 1 5 1. 05 0. 49 0. 0 99. 5 2. 1 0. 0 11 Erueic acid 1 5 3. 55 1.66 0.2 98. 1 1.0 0. 1 12 Fatty acid mixture Cs/Cio 7 3. 11 1.42 0. 0 98. 9 5. 1 0.1

I 95%. 1 Composition: Ca=41.0%, C1o=59.0%.

EXAMPLES 13-14 The commercial oleic acid used in Example 1 and a degrees of reaction and that the color quality drops considerably compared to the examples of the invention.

TABLE V Reaction Percent Lovibond color Carboxylie Cata- Temp. Time Acid Free Free acid Amine lyst C (hours) N 0. acid Amine Amide Yellow Red Oleic acid (CHmNH 195 14 4. 88 3. 41 0. 0 96. 6 42. 0 6. 3 Do- (CH3)2NH HaBO; 195 9 2. 23 1. 09 0. 14 98. 8 11. 0 0. 9

Do (CH3)2NH A110: 195 10 2. 43 1. 19 1. 53 97.3 14.0 3. 2 Do CHaNHz 195 0. 95 0.59 0. 10 99.3 12. 2 0. 8 Stearic acid (CH3) 2N H 195 13 3. 78 1. 84 0. 0 98. 2 17. 2 3. 0 Do CHaNHz 170 12 3. 49 1. 72 0. 98. 1 14. 0 1. 0

1 Composition as in Example 1.

1 Composition as in Example 14.

technical stearic acid of the composition (C-12 1.1%, C-l4 2.6%, C16 45.3%, C18 51.0%, acid number 209.2, saponification number 210.0, iodine number 0.5, titer 55.8 C.) were reacted with methyl amine in the presence of 1% by weight of tetrapropyl zirconate at the respective reaction temperatures in a procedure similar to Example 1. The results are shown in Table EXAMPLES l5-17 kg. each of a substantially equimolar mixture (molar ratio car-boxylic acid: amine--l:1.05) of the oleic acid described in Example 1 and of a primary coconut amine (composition-C8 5.5%, C-l0 6.4%, C-12 47.1%, C-l4 18.2%, C-16 10.0%, C-18 12.8%) were heated to 165 C. in a vessel provided with a stirrer, condenser and TABLE IV Percent Lovibond color Reaction value Ex. Carboxylic temp. Acid Free Free No. acid 0.) number acid Amine Amide Yellow Red 13 oleic acid 195 1. 12 0.55 0. 15 99. 3 1.4 0.0 14 stearic acid.... 170 1.60 0.79 0. 10 99. 1 1. 9 0. 1

Comparison tests The reaction of the oleic acid described in Example 1 and of a technical stearic acid according to Example 14 was repeated with dimethyl amine and methylamine without a catalyst, and in the presence of the compounds boric acid and alumina known as catalysts for the reac- TABLE VI Reaction Percent Lovibond color value Temp. Time Acid Free Free Catalyst 0.) (hours) No. acid amine Amide Yellow Red Example N 0.:

15 Tetrapropyl zirconate 165 4 3. 37 1. 0. 0 98. 4 4. 9 0. 1 Titanium acetyl acetonate. 165 5 2. 50 1. 23 0. 41 98. 4 5. 1 0. 3 Titanium polyhydroxy stearat 165 5 1. 88 0. 92 1. 46 97. 6 6. 3 0. 1 165 11 7. 3. 84 4. 38 91. 8 14. 2 2. 0 10 1. 53 0. 75 1. 88 97. 4 20. 0 4. 2 165 9 3. 15 1. 54 1. 10 97. 4 23. 1 3. 4

l Aeyl compound with Ae=stearoyl.

EXAMPLES 18-24 a molar ratio of carboxylic acid: alkylene diamine= In a similar manner, the fatty acid mixtures mentioned 2:140 and of the respective mixture was used below were reacted in the presence of 1% by weight of each case.

TABLE IX Percent Reaction Gardner Example time Acid Free Free color No. Catalyst (hours) No. acid amine Amide value Tetrapropyl zirconate 5 2.92 1.44 0.61 98.0 4-5 5 1.24 0.70 0.92 98.3 5-0 4 0.42 0.23 0.78 99.0 4-5 4 2.19 1. 36 1.20 97.4 5-6 1 Acyl compound with Ac=stearoyl.

tetra-propyl zirconate at 165 C. with the above-described EXAMPLES coconut amme. The results are reported 111 Table VII. In the Same quantitative ratios and with the Same TABLE VII Percent Lovibond Reaction color Example time Acid Free Free No. Carboxylic acid (hours) No. acid amine Amide Yellow Red 18 Soya fatty acid 6 1.58 0.78 1.22 98.0 2.7 0.1 19-- Rape 011E01d 0 1. 30 0.70 1.02 98.2 3.0 0.1 20-. Sperm oil acid- 5 3. 59 1.71 0.39 97.9 0.8 0.1 21-. Trane oil acid--. 5 2.98 1. 48 0.82 97.7 1.5 0.2 22.. Tallow fatty acid...... 5 2.78 1.37 0.60 98.0 1.2 0.1 23-.- Fatty acid mixture 01/010 4 0.86 0.24 1.34 98.4 0.8 0.1 24 Erucic acid 95% 3 2.37 1.36 0.57 98.1 2.0 0.1

1 Composition: Cr=41.0%, Cio=59.0%. I Balance: C20=0.5%, Cz0=I 2.0%, C21=1.9%.

EXAMPLES 25-31 procedure as in Example 32, the reaction was carried The Examples 18 (to 24 were repeated with the excep 3 out between the carboxylic acids and alkylene diamines tion that a tallow amine (composition C-14 6.5% C-16 mentioned below in the Presence 0f 1% y Weight of 31.4%, C-18 62.1%) was used instead of coconut amine tetra-propyl zirconate.

TABLE X Reaction Percent Gardner Temp. Time Acid Free Free color Example No. Carboxylic acid 0.) (hours) No. acid amine Amide value (a) Ethylene diamine:

36 Stearic acid, technical 165 4 1. 38 0. 67 0. 68 98. 7 3-4 37 do 195 3 1. 29 0. 64 0. 74 98. 6 6-7 33 Leunc acid 165 6 0. 50 0. 19 0. 81 98.9 45 0 Myristic acid 165 4 2. 11 1. 05 0. 10 98. 9 34 Erucic acid 95% 165 4 2. 1. 42 0. 9 97, e .5 (b) Propylene diamine:

41 Stearic acid, technical 165 6 4. 31 214 1 4,5 96 4 4. 42 do 195 5 2. 12 1. 17 0. 86 98. 0 5-6 42 Palmiti acid 165 6 3. 23 1. 48 0. 56 98. 0 3-4 4 (in 195 6 1. 05 0. 76 0. 88 98. 4 6-7 45 Erucic 6 165 7 4. 13 2. 40 1. 58 96.0 5-6 (0) Hexamethyleue diamine:

46 Stearic acid, technical 1 165 4. 5 1. 91 0. 91 0. 04 99. 0 2-3 47 do 195 2. 5 1. 81 0. 89 1. 03 98. 1 8-4 4 Myrigtic acid 165 5. 5 2. 90 1. 44 0. 36 98. 2 5 49 Paimitic acid 165 5 0. 62 0. 28 0. 35 99. 4 4-5 an Em i mid 165 4. 2 1. 32 0. 65 0. 43 99. 0 4-5 209.2, saponification number 210.0, iodine number 0 scomposition: C =1.1%, O r=2.6%, C =45.3%, Cn=51.0%; acid number and that the reaction temperature was kept at 195 C. The Comparative tests of the reaction of technical stearic results are in Table VH1. 55 acid with hexamethylene diamine without catalysts TABLE VIII Percent Lovibond Reaction Color Example time Acid Free Free No. Carboxylic acid (hours) No. acid amine Amide Yellow Red 1 Composition as in Example 23. 1 Composition as in Example 24.

EXAMPLES 32-35 showed that a comparable degree of reaction could only I be achieved by tripling the reaction time while the color In a test similar to Example 15, palmitrc acid of comof th d t d t ri t d,

98.0 mercial quality (composition C-14 10%, C 16 EXAMPLES 51 AND 52 C-l7 1.0%) was reacted with ethylene diamine in the presence of 1% relative to carboxylic acid of the catalysts In the procedure according to Examples 1 and 15 to 17, mentioned below at C. The reaction took place in commercial oleic acid (sec Example 1) was reacted with 9 dimethyl amine and with primary coconut amine resp. described in Examples 15 to 17 in the presence of 1% by weight of ground tin.

3. The process of claim 2 wherein the amount of catalyst is 0.5 to 5%.

TABLE XI Percent Reaction Lcvibond color Example time Acid Free Free No. Amine hours No. acid amine Amide Yellow Red 51 (CHa)2NH 6 2.20 1.06 0.13 98.8 4.7 0.9 52 Coconut amine. 4 1.96 0.96 0.94 98.1 3.1 2.0

EXAMPLE 53 4. The process of claim 1 wherein the reaction is Using the procedure of Examples to 17, 9-hydroxystearic acid was reacted with the above-described primary coconut amine in a molar ratio of 1:105 in the presence of 1% by weight of tetrapropyl zirconate at 195 C. to obtain a product which contained 83% amide and 12% ester as well as 2.6% free acid.

The advantages achieved with the invention consists primarily in that substituted carboxylic amides are made accessible by reacting carboxylic acids with amines in an economical method with a high degree of purity. Particularly noteworthy is the relatively short reaction time which is necessary for a complete reaction and the excellent color quality of the products. Important also is that an excess of amines, which could lead to a higher expenditure in the processing of the products, is not required.

Various modifications of the process of the invention may be made without departing from the spirit or scope thereof, and it is to be understood that the invention is not intended to be limited only as defined in the appended claims.

We claim:

1. A process for the preparation of N-substituted amides of aliphatic carboxylic acids comprising reacting a primary or secondary amine with a member of the group consisting of aliphatic carboxylic acids of 8 to 24 carbon atoms and esters thereof with aliphatic alcohols in the presence of a reaction-soluble catalyst compound of a metal selected from the group consisting of a tantalum halide or a zirconium or titanium compound selected from the group consisting of ortho acid esters with alcohols, complexes with 1,3- diketones, halogen compounds and acyl compounds.

2. The process of claim 1 wherein the catalyst used is 0.1 to 10% by weight based on the carboxylic acid compound.

effected at to 300 C.

5. The process of claim 3 wherein the reaction is elfected at to 200 C.

6. The process of claim 1 wherein the amine is a higher boiling amine and is used in a 5 to 10% molar excess with respect to the acid compound.

7. The process of claim 1 wherein the reaction is effected at atmospheric pressure.

8. A process for the preparation of N-substituted carboxylic acid amides comprising reacting at 100 to 200 C. a primary or secondary amine with a member of the group consisting of a carboxylic acid of 8 to 24 carbon atoms and esters thereof with aliphatic alcohols of 1 to 4 carbon atoms at normal pressures in the presence of 0.1 to 10% by weight based on the said compound, of a metal catalyst compound of a metal selected from the group consisting of a tantalum halide or a zirconium or titanium compound selected from the group consisting of ortho acid esters with an alcohol, halides, complexes with aliphatic 1,3-diketones and polyhydroxy acylates.

References Cited UNITED STATES PATENTS 3,324,179 6/1967 Scholz et a1. 260-561 3,590,057 6/1971 Suzuki et a1. 260404 1,991,956 2/ 1935 Ralston 260404 2,013,108 9/1935 Reppe et a1. 260-404 2,794,043 5/ 1957 Jansen et a1. 2 60404 LEWIS GOTTS, Primary Examiner E. G. LOVE, Assistant Examiner US. Cl. X.R. 

